Question

好的我开始新鲜，我将承担我所拥有的一切。

NumbersMake.py

#This program writes 1 line of 12 random integers, each in the
#range from 1-100 to a text file.

def main():

    import random

    #Open a file named numbers.txt.
    outfile = open('numbers.txt', 'w')

    #Produce the numbers
    for count in range(12):
        #Get a random number.
        num = random.randint(1, 100)

        #Write 12 random intergers in the range of 1-100 on one line
        #to the file.
        outfile.write(str(num) + " ")

    #Close the file.
    outfile.close()
    print('Data written to numbers.txt')

#Call the main function
main()

上面的代码会生成一个文本文件：

60 90 75 94 54 12 10 45 60 92 47 65

上面的数字是由空格分隔的12个随机生成的整数。

如果删除空格，第二个脚本会更容易吗？

NumbersRead.py

#This program reads 12 random integers, outputs each number
#to its own line and then outputs the total of the even and odd  intergers.

def main():

    #Open a file named numbers.txt.
    infile = open('numbers.txt', 'r')

    #Read/process the file's contents.
    file_contents = infile.readline()
    numbers = file_contents.split(" ")
    odd = 0
    even = 0
    num = int(file_contents)
    for file_contents in numbers:
        if num%2 == 0:
            even += num
        else:
            odd += num

    #Close the file.
    infile.close()

    #Print out integer totals
    print('The total of the even intergers is: ', even)
    print('The total of the odd intergers is: ', odd)

#Call the main function
main()

我从上面的脚本中收到的错误是尝试处理偶数和奇数的总和：

Traceback (most recent call last):
  File "numbersread.py", line 29, in <module>
    main()
  File "numbersread.py", line 14, in main
    num = int(file_contents)
ValueError: invalid literal for int() with base 10: '60 90 75 94 54 12 10 45 60 92 47 65 '

我不知道我做错了什么。

Answer 1

假设您有一个类似["1","2","3"...]

的列表

odd = sum(int(x) for x in  numbers if x % 2)
even = sum(int(x) for x in  numbers if not x % 2)

最好的方法是使用with打开文件并首先映射到int：

with open('numbers.txt') as f: # closes you files automatically
    numbers = map(int,f.read().split())


    odd = sum(x for x in numbers if x % 2) 
    even = sum(x for x in numbers if not x % 2)

如果你有一个非常大的文件，你将遍历每一行并总结你的总和。

如果您只希望第一行将readline替换为f.read().split()

，那么您只能使用f.readline().split()阅读一行

sum(x for x in numbers if x % 2)是generator expression，生成器表达式中使用的变量在为生成器对象调用 next （）方法时会被懒惰地计算

Answer 2

这看起来很像我的家庭作业，但这就是我用来代替你的while循环

for num_str in numbers:
  num = int(num_str)
  if num%2 == 0: #Even
    even += num
  else:
    odd += num

如何选择偶数和奇数整数并得到它们的总数

2 个答案: